Method of curing rubber



Patented Jan. 13, 19

"UNITED. STATES; PATENT OFFICE. I

WALDEMAR O. HAMIS'LER AND VICTOR SIGNORS OF ONE-HALF TO O. HAM'ISTEB, rm: GOODYEAR TIRE & RUBBER COMPANY, or AKRON,

or CLEVELAND, 01110, As-

OHIO, A CORPORATION or OHIO, AND ONE-HALF TO NATIONAL CARBON COMPANY,

OF NEW YORK, Y., A OO rOR 'rIO-N on NEW YORK.

METHOD OF CURING RUBBER.

.No'Drawing.- Application filed October To all whom ii may concern Be it known that ,we, 'Amnaimu O. HAM- Is'rEu, a citizen of the United Statesba'nd resident of Akron. Ohio. and VICTOR -C. Hnsrrs'rrn, a citizen of the United States. and resident of Cleveland. Ohio. hare-invented new and useful Improvements in h'lethods of Curing Rubber, of which the following is a specification;

.Our invention pertains to the manufacture of rubber and it. has particular relation-to that .step of the manufacturing process known as vulcanization in which the curing of the rubber is effected. I Oneo'b ect of our invention is to provide a .novelm'ethod of introducing vulcanizmg agents into a rubber compound. Another ob-,

ject of our inventioniis to provide a slmplei and inexpensive method whereby rubber may i or :fillers, particularly .in vpowdered be cured without the aid of heat.

Heretofore, in the vulcanization-Of rubber: b\'' treatment with gases, such, for example,

as hydrogen sulphide and sulphur dioxide, difficulty has-been experiencedin' introducing the hydrogen sulphide into the rubber the low. solubility wve-hawe provided a method'of introducing any desired gas into the rubber cement, whereinthe difiicultieskwhich obtained by reason of the low rubber cement, areisolubility oi the gas in V eliminated.

'- rubber through Another method of curing at present em-' plovedconsistsin passing asheet of uncured a container filled with sulphur dioxide. This method is objectionable ofi; sealing the gas chambers, especially in installations in which the cure m'ustbe continuous for continuously moving material. This 'diiliculty' is also avo ded by our invention, because both gases wl; in interact sired be introduced into the rubber in the milling process.

. In practicing our invention, we take advantage of the gas absorbing propertiesof certainpigments or fillers, more particularly phide, rubber, which .is usually acco As finely divided carbon is fre-' 'lampblack-and other hydro-carbons present to efiect the cure" may if de- 30, 1925 2. Serial No. 598,006.

those of a carbonaceous nature. We have found, for example, that finely divided carbon may be-saturated. with'a suitable gaseous vulcanizing agent, such as hydrogen sulhe't'ore being introduced into the 'plished' by milling. quently employed in the :manufacture of rubber asa pigment,- and in order to toughen the stock, no new and und'esir'ablefoi unnecessary elements are added to mixture by practising-our invention. Sulphur dioxide, which reacts with hydrogen sulphide toproducethe sulphur necessary to vu-lcanize the rubber, may a similar manner if"desired,.b1'1t'on account I, ofthefreadysolubility of this gas, such treatment is'considered. unnecessary. J

the rubber be introduced in --'.Althoughit.is. possible tO- utilize pigments other than carbon, it is liighlygdesirable that an agent having a relatively high adsorptive capacity ior gases .-be;- em'ployed. This property s possessed which has been subjected to a-treatment, known as activation. The activation of car-- bon consists essentially in raising the crude temperatureof approxi form,

too. modifieddegree'byfinely .divided carbon mateIy SOO to 900 G. in the presence-of a limitedainount of oxygen, steam, air, carbon dioxide, or equivalent reagents. When treated asdescribed, the

inthe lampblack, or other raw carbon, are ess of selective Oxidation. This leaves a.

carb on aceo u sbase or skeleton which posjsesses a relatively high adsorptive capacity A in the 'formof eliminated by a procfor gasesand is usually designated as acti-- vated carbon.

In manufacturing rubber in accordance with-our invention, -we prefer activated carbon with hydrogen sulphide and tomill the same into the-rubber, thus thou oughly mixing the'rubber, the carbon and the gas A cement 's the'nma'de from the mixture by the addition of a relatively small to saturate gen sulphidefromthe, carbon to facilitate its interaction with the sulphur dioxide.

quantity ofiabric, the solvent saturated with the sulphur dioxide should be mixed with the cement containing the hydrogen sulphide but a veryshort time before applying the mixture to the fabric. As. a-.- short interval-of time is'necessary for the complete vulcanization of the-rubber 'it'will'not-be vulcanized v until after being p'lacedin its final position on the fabric.

The rubber passing it through a chamber containing sulthe hydrogen sulphide phur dioxide, the interaction of which with cure.

a quantity of separatedfiber are provided with individualrubber coverings and are: then-arranged in a matted formation in any desired shape. It is highly desirable in-the manufacture of material of the character queStmnIthat the cure of the rubber be effect'ed without heating to any'great extent because the. fibers in the material are likely to be charred and seriously damaged if i raised to a high temperature, thus injuring In 'inanufacturing artificial hydrogen sulphideshould be introduced into the rubber solution prior to the deposition of the rubber on the individual fibers. Thesulphur dioxide may be introduced vthereto either before, during, or after the actual precipztatlon of the rubber on the fibers, or

after the fibers are molded to form and dried.

' It is desirable, insome instances, to heat theimixtureof which thei'activated carbon forms a ortion, at the time of adding the sulphur ioxide, inorder, to drive the hydro- Al so itmay be desirable to impregnate a portion of the carbonaceous'or other pig- .ment.or filler with hydrogen sulphide and another portion with sulphur dioxide, and. mill both into the rubber, the cure being I effected atany stage ofthe process by heat- 'ingthematerial, thus driving the gases from :the filler and into contact witheach other.

Furthermore, if desired, a quantity of fine-;

1y divided carbon or other pigment, or filler,

having sufiicient adsorptive capacity for.

inay also be cured by constructing a piece of material or an article .into by means of an activat produces the desiredv I i 5 comprises introducingsulphur thereinto by Our inventionimay' 'i's'e be applied .to.

thomanufacture of artificial leather in which sively through. chambers containing hydro- Although we have set forth several slight- "ly difi'erent form's which our invention may a'ssumeand havedescribed in detail several applications thereof, itwill-be obvious to- :ose skilled in theart that our invention is not so limited but that various minormodifications and changesmay be made therein without departing from the .s iritof our" invention or from the scope of t e appended claims. .4 i

'Whatfwe claimis: i 1. The method of treatingrubber which comprises introducing a curing agent thereinto co'mbined'with a pigment. 2. The method of treating rubber which comprises introducing acurin agent thereigment.

3'. .The method of treating ru her which means of activatedcarbon.-

. 4. The method of treating rubber which comprises introducinga rubber curing-fluid thereinto .by means of a solidcarrying a cut.

comprises introducinga rubber-curing gas -.thereinto by. means of a pigment in powdered form.

7; The methodof treating rubber which comprises introducing hydrogen sul hide by means of im regnateil carbon, an subsequently treating the mixturewith sulphur dioxide. 4 I

' 8. The method of-treating rubber which comprises introducin into the rubber a pig{ I ment impregnated with hydrogen sulphide. 9. The method of treating rubber which comprises impregnating a quantity of carbon with hydrogen sulp ide, milling the carbon into the rubber making said rubber into a cement, an'dfmixmg therewith a quantity of rubber solvent containing a quantity of sulphur dioxide.

10. Themethodof treating rubber which comprises impregnatin a quantity of carbon with'hydrogen sulphi e, milling the carbon into the rubber, making said rubber into a cement, mixing therewith a quantity of rubber solvent containinga quantity of sulphur dioxide, and heating'themixture. 1

- 11. The method of treatingrubbei' which comprises introducing into the rubber hydrogen sulphide and sulphur. dioxide by meaiis of pow erimpre 'ated therewith.

12. The meth of treating rubber which comprises milling a powder ;ada ted to be activatedintoa rubber compoun and sub sequentiy treating the compound with rubsigned our nanies in the presence of two sub ber curlng gases. scribing witnesses.

13. The methodof treating rubber which WALDEMAR O. HAMISTER. comprises milling a quantity of powder Witnesses:

5 adapted to be activated into a rubber com- F. A. LIND, pound, and subsequently passing the com- 0. E. BEE. pound successively through chambers con- VICTOR O HAMISTER taining hydrogen sulphide and sulphur Witnesses. dioxide respectively. JOHN'FLEINSMITH 10 In witness whereof, we have hereunto 

